In the fields of agriculture and forestry, efforts have been made to produce plants with increased growth potential in order to feed the ever-increasing world population and to guarantee the supply of reproducible raw materials. This is done conventionally through plant breeding. The breeding process is, however, both time-consuming and labor-intensive. Furthermore, appropriate breeding programs must be performed for each relevant plant species.
In addition, plants are constantly exposed to a variety of biotic (e.g., pathogen infection and insect herbivory) and abiotic (e.g., high or low temperature, drought, and salinity) stresses. To survive these challenges, plants have developed elaborate mechanisms to perceive external signals and to manifest adaptive responses with proper physiological and morphological changes (Bohnert et al., 1995 Plant Cell, 7:1099–1111). Plants exposed to low water or drought conditions typically have low yields of plant material, seeds, fruit and other edible products. Some areas of the world consistently have very low rainfall and therefore have problems growing sufficient food crops for their population. Yet it has been observed that some plants survive and thrive in low water environments. To avoid reliance on breeding processes, it would be useful to identify genes that confer improved drought tolerance to enable the creation of transformed plants (such as crop plants) with improved drought tolerance characteristics.